The train passes a traffic light in 5 seconds, and a platform 200 meters long in 15 seconds. Find the length of the train and its speed.

First, let’s calculate the speed of the train.
If we know that the platform is 200 meters long, and the train passed it in 15 seconds.
So we need (200) the length of the platform, we divide by (15) the time.
200: 15 = 13.3.
Now, if the train passes the traffic light in 5 seconds.
So, to calculate the length of the train, you need (13.3) the speed of the train, multiply by (5) the time.
13.3 * 5 = 66.5.
Answer: The train speed is 13.3 meters per second.
The train length is 66.5 meters.